1. Field Of The Invention
This invention relates to bridge plugs for use in wells, and more particularly, to a packer-type bridge plug which may be set upon a wireline and retrieved upon a tubing string for use in wells.
2. Description Of The Prior Art
In oil and gas wells it is desirable to have a bridge plug which will withstand high differential fluid pressures thereacross, can be set using a wireline and can be easily retrieved from the well. Such a bridge plug is particularly deirable when wells with multiple formations are to be isolated for completion, testing and/or stimulation.
One bridge plug so designed is disclosed in U.S. Pat. No. 4,545,431 to Fore, assigned to the assignee of the present invention. One problem with the apparatus of Fore is that some portions of the bypass passages therein are open above the packer element. Sand may settle on top of the set bridge plug, blocking these passages and getting into the apparatus. This can prevent proper actuation and cause difficulties on retrieval. In the present invention, all bypass passages are always closed prior to retrieval. Also, the ratchet, slips and J-slot are below the packer and thus protected.
Other typical prior art retrievable packers and bridge plugs are disclosed in U.S. Pat. Nos. 3,244,233; 3,507,327; 3,584,684; 3,749,166; 4,078,606; and 4,427,063.